End-thrust counterbalance for centrifugal pumps and shafting.



Patented lan. 29, |690I.

F. H. JACKSON.

(Application med sept. 7,1699.)

END THRUST CUUNTERBALANCE FOR CENTBIFUGAL PUMPS AND SHAFTING.

(No Modal.)

UNITED STATES PATENT OFFICE.

FRANK H. JACKSON, OF SAN FRANCISCO, CALIFORNIA.

END-THRUST COUNTERBALANCE FOR CENTRIFUGAL PUMPS AND SHAFTING.

SPECIFICATION forming part of Letters Patent No. 666,869, dated January29, 1901.

Application filed September '7, 1899. Serial No. 729.679. (No model.)

To all whom it may concern:

Be it known that I, FRANK H. JACKSON, a citizen of the United States,residing in the city and county of San Francisco, State of California,have invented an Improvement in End-Thrust Counterbalances forCentrifugal Pumps and Shafting; and I hereby declare the following 1o bea full, clear, and exactdescription of the same. a

My invention relates to end-thrust coun.- terbalances for centrifugalpumps and shafting; and it consists of the parts and the constructionsand combinations of part-s hereinafter described and claimed.

Figure lis a sectional View showing the runner revoluble in a horizontalplane. Fig. 2 shows the runner upon a horizontal shaft and running in avertical plane.

It is well understood by those familiar with centrifugal pumps that thedischarge pressure between the runner andthe case is never equal to thetotal discharge pressure in the involute of the case or thedischarge-pipe of the pump and that these variations will cause anunequal pressure on the two sides of the runner, which has a tendency toforce it in one direction or the other if not held in place by collars.This variation and end thrust also occurs either from the weight of theshaft and attached parts when running vertically or from action of thepropelling mechanism or the unequal hydraulic pressure caused byvariations of the suction on one side and the variations in the pressurefrom the discharge.

It is the object of my invention to automatically regulate thesepressures and so counterbalance the runner or impeller that it willalways remain approximately central within the case without the aid ofcollars or other mechanical support.

In my improvement the runner or impeller is constructed withrunning-joints, the joint upon the opposite side from thesuction-entrance having approximately about the same diameter as that ofthe suction-entrance, this being varied, however, to produce anequilibrium between the counter-thrusts. In other Words, a flange Gprojects from one side of the runner into the suction-chamber (above therunner in Fig. l) and another [lange H projects below the runner. Bothof these flanges turn in corresponding sleeves or flanges, the lower onebeing lettered H in Fig. l, and said flanges are slidable up or down asthe runner rises or sinks. The discharge pressure reaches the chamberWithin the liange opposite to the suction side of the runner through therunning-joint of this flange, and when this pressure exceeds that of thesuction side a slight movement of the wheel toward that direction partlyopens a central passage, which discharges the surplus pressure byconnecting this chamber directly with the suction.

The main casing C is volute in form having the peripheral dischargespace, as shown. Within the central portion of the casing is the runneror impeller D, so called, which is fixed upon the driving-shaft M,suitably journaled and extending into the case, as shown. Power isapplied to this shaft in any suitable or desired manner to give motionto the runner. This runner is of the inclosed form and consists of disksor sides having hollow arms or vanes extending from the central portionto the periphery. When power is applied to rotate this runner, the pumpbeing properly primed, the centrifugal action will draw water throughthe suction or inlet pipes E and through the inlet-openings F in therunner, discharging it outwardly into the peripheral discharge-passageC.

The impeller has a flange G extending into the suction-passage andforming a runningjoint therein. Upon the opposite side of the impelleris a projecting flange or ring H,which enters into and forms arunning-joint with a corresponding flange H upon the side of the caseopposite to the suction. These flanges G and H are movable in theirrespective chambers, and they form the dividing-line between the suctionand discharge pressures. Openings I are made through the disk of theimpeller opposite to the suction, and a central opening I connects thisspace With the space K,which is formed Within the running-flanges H H'.

J is a plug or projection central within the 4chamber K and of suchdiameter that it fits the passage I when the impeller is forced awayfrom the suction-inlet, and when the impeller moves toward the suction-inlet it will be withdrawn from this plug or projection, so as to leavean open passage between the cham- IOO ber K through the openings I and Ito the suction-inlet.

Vhen the machine is in operation, the pressure due tothe dischargesurrounding the impeller or runner will be admitted through therunning-joint between the flanges H a-nd H', and thus produce a pressurein the chamber K, which in the case of the vertical arrangement of thepump serves to support the weight of the running parts and in anyarrangement to resist any thrust in that direction. Whenever thepressure within this chamber is greater than t-he pressure from theopposite side, the runner will be moved a short distance until thepassage I' is opened by reason of the runner having moved away from theprojection .I until it passes more water than can pass the running-jointH and H', thus allowing the surplus pressure to pass directly throughthe openings I into the suction-inlet of the pump. XVhencver thepressure from the opposite or suction side is greater than that from thedischarge side, the runner will move slightly until the passage I fitsover the projection J, when the pressure from' the discharge enteringthe chamber K will again act to resist further movement in thisdirection. In this manner the differential of pressure upon one side orthe other acts constantly to balance the runner and retain it in itsproper central position where the unequal balance is caused by hydraulicpressure, the gravity of the moving parts, or the drivingT force, therunner being held in equilibrium approximately in the center of the pump-case without the use of thrust collars or bearings, and the result isthe same whether the shaft is vertical, horizontal, or whether the pumpsare simple or compounded. It will be obvious that this balancing may beeffected by any available hydraulic pressure upon one side and anysuitable discharge or relief upon the opposite side and may be appliedto revolving shafts other than those of centrifugal pumps, such as thepropeller-shaft of a steamship, the vertical shaft in flour-mills, orwater-wheels, and any other power plants where the hydraulic pressuremay be produced by a pump installed simply for the purpose of hydraulicpressure.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

l. In a centrifugal pump, the combination of a case, an inclosed runneror impeller mounted upon a shaft and revoluble Within the case, asuction-inlet passage concentric with the shaft upon one side of thecase, an annular flange projecting from the impeller intosaidinletfortningarunning-jointtherein, a corresponding flangeprojecting from the opposite side of the runner, an annular flangeprojecting from the casing forming a chamber into which the said tlangeof the runner extends and is revoluble, a passage connecting saidchamber with the suction-inlet and a central plug or piston controllingsaid passage.

2. In a centrifugal pump, the combination of an exterior casing, arunner mounted upon a shaft and revoluble within the casing, said runnerhaving closed sides and radial van es or passages, a suction-inletconnecting with the casing and the interior of the runner around theshaft upon one side, passages through the opposite side of the runner, achamber formed in the opposite side of the case, annular flanges formedupon opposite sides of the runner, one forming a runningjoint in thesuction-inlet and the other a similar joint. in the chamber upon theopposite side,said chambcrrcceiving pressure from the discharge of thepump, a passage made centrally through the hack of the runner andconnecting the suction-inlet directly with the rear chamber, and a plugor piston over which said passage tits and is movable to close or opencommunication between the chamber and the suctioninlet.

3. The combination in a centrifugal pump of an automatic balancingdevice consisting of annular [langes projecting from the opposite sidesof the inclosed runner, one of said flanges forming a running-jointwithin the relief-passage, and the otherl extending into and forming asimilar joint in a chamber formed upon the opposite side of the casing,passages connecting the discharge and the interior of the runner withsaid chamber and a plug or piston with relation to which the runner ismovable in the line of its axis so as to close or open said passages.

In witness whereof I have hereunto set my hand.

FRANK H. JACKSON.

Witnesses:

J oHN W. NYE, LEE D. CRAIG.

